Cutting wire assembly with coating for use with a catheter

ABSTRACT

A device for treating a lesion in a body lumen to enlarge a passageway in the body lumen having at least one cutting member and a tracking member. The at least one cutting member has a cutting surface and a separate material associated therewith. The cutting member and tracking member are connected at a distal portion and insertable into the body lumen as a unit, the cutting member configured for movement in a direction transverse to a longitudinal axis of the tracking member to widen a gap between the cutting member and tracking member at least at a distal region and to apply the separate material to an interior of the lesion.

BACKGROUND

This application claims the benefit of provisional application Ser. No.61/861,988, filed Aug. 3, 2013, and is a continuation-in-part ofapplication Ser. No. 13/226,735, filed Sep. 7, 2011, now U.S. Pat. No.8,685,050, which claims the benefit of provisional application Ser. No.61/390,217, filed Jun. 10, 2010, and a continuation-in-part ofapplication Ser. No. 13/226,699, filed Sep. 7, 2011, now U.S. Pat. No.8,685,049, which claims the benefit of provisional Ser. application No.61/414,931, filed Nov. 18. 2010. The entire contents of each of theseapplications are incorporated herein by reference.

TECHNICAL FIELD

This application relates to a system and method for treating stenoticlesions of a vessel and more particularly relates to a cutting wire foruse with a catheter to open stenotic lesions in vessels.

BACKGROUND OF RELATED ART

Several methods have been utilized to treat stenotic lesions of vessels.With stenotic lesions, the vessel diameter is constricted and thereforeattempts have been made to widen this constriction. One method is aninvasive surgical procedure where the vessel wall is cut open and theportion containing the plaque or other constricting structure isremoved. This procedure is traumatic, complex, and results in a longrecovery time for the patient. It also causes a weakening of the vesselwall since a portion of the wall is removed. A weakened wall canultimately result in an aneurysm which is a dilatation (expansion) ofthe artery, which adversely affects vessel function and if notsurgically treated could be life threatening to the patient.

In order to reduce trauma to the patient, reduce the patient recoverytime and reduce hospital costs, minimally invasive procedures have beendeveloped to treat stenotic lesions. Balloon angioplasty is one suchmethod. In angioplasty, a balloon is placed in the stenosed (restricted)portion of the vessel and inflated to compress the plaque against thevessel wall, thereby increasing the lumen in the vessel to improve bloodflow. That is, the balloon is inflated to push the lesion radiallyoutwardly to widen the passageway. Some stenotic lesions are resistantto conventional pressure balloons. Consequently, high pressure balloonshave been developed to treat resistant stenotic lesions. However, suchhigh pressure balloons apply more force and increase the risk of vesseltrauma and rupture. Moreover, sometimes lesions are even resistant tothese high pressure balloons.

Additionally, the use of these angioplasty balloon catheters oftentimeshave only short term effect as it has been found that restensoisfrequently occurs after such treatment.

In an attempt to address such drawbacks as reducing the likelihood ofrestenosis and trauma, as well as to treat vessels with highly resistantlesions, cutting balloon catheters were developed. One such device isdisclosed for example in U.S. Pat. No. 5,196,024 which describes acatheter with a balloon and longitudinal cutting edges. One of the manydisadvantages of this device, however, is it requires modifications ofballoon catheters which significantly increases the cost of thecatheter. Another disadvantage is that instead of using the proceduralcatheter, a different catheter may be required with a cutting balloon.Consequently, the surgeon would need to decide prior to the procedurewhich type of catheter to utilize, although this may not always bepractical as the information to determine the type (e.g. resistance) ofthe lesion may not be available until the lesion is accessed and theextent of the disease is known. Thus, for example, the surgeon mayinsert an angioplasty catheter, inflate the balloon and find that it isinsufficient to widen the vessel passageway. The surgeon would then needto conduct the time consuming task of removing the catheter andinserting a cutting balloon catheter, threading it through the vascularsystem over a guidewire. Since the catheters are inserted from a remotesite, e.g. through the femoral artery, these catheter exchanges taketime and increase trauma to the patient. Additionally, it adds to thecost of the procedure since two catheters would be required. In order toproperly treat the diverse size and condition of each lesion a largeinventory of multiple sized cutting balloons would be required.

Conversely, in certain procedures, utilizing a cutting balloon in softlesions increases the risk of trauma or damage to the vessel andtherefore it would not be desirable to use a cutting balloon catheter.Thus, an exchange for an angioplasty catheter would be necessary.

Such catheter exchanges might also require guidewire exchanges since thestandard 0.035″ guidewire utilized for an angioplasty catheter may betoo large for the 0.018″ cutting balloon catheter. The guidewireexchanges complicate the procedure, increase the risk to the patient andincrease the procedure time, thereby increasing costs to the patient.

U.S. Pat. No. 7,131,981 attempts to address the foregoing issues byproviding a conversion device comprising an insertion tube insertableinto the normal 0.035″ guidewire lumen of an angioplasty catheter. Thisdevice would not work for angioplasty catheters with small guidewirelumens. The tube has two jacket segments and a guide insert devicehaving a channel and four guide channels. Because of the complexity ofthe device, the cutting elements in the four channels would need to besufficiently thin to be maintained in the smaller diameter device. Suchthin (small diameter) cutting elements however may be too flexible andnot have adequate stiffness to be effective. Additionally, the cuttingelements are attached at one end, having an opposite free end which canpotentially damage and perforate the vessel wall during use.

The need therefore exists for an improved, more simplified device andmethod to enable the selective use of a cutting wire for treatingstenosis. U.S. patent publications 2012-0089163 and 2012-0130408disclose effective devices for treating stenosis. However, it would beadvantageous to enhance in certain procedures plaque/clotdisruption/dissolution and/or enhance plaque/clot prevention utilizingthe cutting wire.

SUMMARY

In one aspect, the present invention provides a method of treating alesion in a body lumen comprising inserting a tracking member and atleast one cutting member having a separate material associated therewiththrough a first lumen of a catheter, withdrawing the catheter from thecutting member and tracking member, inserting the catheter over thetracking member while leaving the cutting member outside the catheter,and expanding a portion of the catheter to move the cutting member intocutting contact with the lesion to enlarge a passageway in the bodylumen and to deliver the separate material into the interior of thelesion.

The separate material described herein can be used with any of theembodiments and is preferably a drug or therapeutic agent. It can forexample be applied on the cutting member as a coating or, in alternateembodiments, embedded therein.

In some embodiments, the step of inserting a catheter over the trackingmember comprises reinserting the same catheter through which the cuttingmember and tracking member were initially inserted. In otherembodiments, a different catheter is utilized.

The catheter preferably includes an expandable balloon, and the step ofexpanding the catheter preferably includes the step of expanding aportion of the balloon to cause the cutting member to be moved radiallywith respect to the catheter. Preferably, the step of expanding aportion of the catheter causes a gap between the cutting member andtracking member to widen.

In another aspect, the present invention provides a method of treating alesion in a body lumen to enlarge a passageway in the body lumencomprising inserting a cutting member and tracking member into thevessel, inserting a catheter over the tracking member so the trackingmember extends through a first lumen of the catheter and the cuttingmember does not extend through, e.g. remains outside, the first lumen,and moving the cutting member away from the tracking member into cuttingcontact with the lesion to enlarge the passageway in the body lumen andto deliver a separate material disposed on or within the cutting memberinto the interior of the lesion.

Preferably, the step of inserting a cutting member and tracking membercomprises the step of inserting the cutting member and tracking memberthrough a lumen of a catheter. In some embodiments, the catheter throughwhich the cutting and tracking members are initially inserted is thesame catheter subsequently inserted over the tracking member. In otherembodiments, a different catheter is utilized. In some embodiments, thestep of moving the cutting member comprises the step of expanding aballoon of the catheter.

In another aspect, the present invention provides a device for treatinga lesion in a body lumen to enlarge a passageway in a body lumencomprising a cutting member having a proximal portion, a distal portionand a separate material and a tracking member having a proximal portionand a distal portion. The cutting member and tracking member areconnected at their distal portions and insertable into the body lumen asa unit, the cutting member configured for movement in a directiontransverse to a longitudinal axis of the tracking member to widen a gapbetween the cutting member and tracking member at least at a distalregion and to deliver the separate material to the interior of thelesion.

In some embodiments, the separate material is disposed on a surface ofthe cutting member, in the form for example of a coating, and ispreferably disposed on the cutting surface of the cutting member. Inother embodiments, the separate material is embedded in the cuttingmember, preferably in the cutting portion, and can leach out into thetarget tissue.

In some embodiments, the cutting member has a cutting surface on a firstsurface opposite a second surface facing the tracking member. In someembodiments, the cutting member has a cutting surface with a flat edgeon an edge opposite a surface facing the tracking member. In someembodiments, the second surface has a convex or concave surface. Thetracking member can include a plurality of marker bands.

In another aspect, the present invention provides a system for treatinglesions in a body lumen to enlarge a restriction in the body lumencomprising a catheter having a lumen and an expandable portion and acutting assembly including a cutting member and tracking member, thetracking member attached to the cutting member. The expandable portionof the catheter is expandable to move the cutting member in a directiontransverse to a longitudinal axis of the tracking member. The cuttingmember includes a separate material and is configured to treat thelesion to enlarge a passageway in the body lumen when moved by theexpandable portion of the catheter.

In some embodiments, the separate material is a coating on the cuttingsurface of the cutting member; in other embodiments, the separatematerial is embedded in the cutting portion of the cutting member.

In preferred embodiments, the cutting member and tracking member arewires.

In some embodiments, the cutting member and tracking member areconnected at distal regions thereof and inserted as a unit through thelumen of the catheter. The tracking member can include a plurality ofmarker bands. The cutting member in some embodiments is substantiallycircular in cross-section in a proximal region and substantiallytriangular in cross-section in a distal region. In preferredembodiments, the expandable portion of the catheter comprises aninflatable balloon.

The tracking member can have a coil at a distal end and a heat shrinkcan be positioned over the attachment region of the cutting and trackingmembers.

In some embodiments, the cutting member has a cutting edge opposite anedge facing the tracking member, and expansion of a portion of thecatheter forces the cutting edge into a diseased narrowed section withinthe lesion.

In some embodiments, the length of the tracking member can exceed thelength of the cutting member. In some embodiments the cutting member hasa first portion of a first configuration and a second portion of asecond configuration, the second portion including a cutting surface andthe first portion being atraumatic. In some embodiments, a height of thesecond portion is less than a height of the first portion.

In some embodiments, the separate material can be placed in or on thecutting surface of the cutting member and not on the atraumatic portion.

In another aspect, the present invention provides a method of treating alesion in a body lumen comprising inserting a tracking member and aplurality of cutting members having a separate material through a firstlumen of a catheter, withdrawing the catheter from the cutting membersand tracking member, inserting the catheter over the tracking memberwhile leaving the cutting members outside the catheter, and expanding aportion of the catheter to move the cutting members into cutting contactwith the lesion to enlarge a passageway in the body lumen and to deliverthe separate material into the interior of the lesion.

The separate material described herein is preferably a drug ortherapeutic agent. It can for example be applied on the cutting wires asa coating or, in alternate embodiments, embedded therein.

In some embodiments, the step of inserting a catheter over the trackingmember comprises reinserting the same catheter through which the cuttingmembers and tracking member were initially inserted. In otherembodiments, a different catheter is utilized.

The catheter preferably includes an expandable balloon, and the step ofexpanding a portion of the catheter preferably includes the step ofexpanding a portion of the balloon to cause the cutting members to bemoved radially with respect to the catheter. Preferably, the step ofexpanding a portion of the catheter causes a gap between the cuttingmembers and tracking member to widen.

In another aspect, the present invention provides a method of treating alesion in a body lumen to enlarge a passageway in the body lumencomprising inserting a tracking member and a plurality of cuttingmembers having a separate material associated therewith into the vessel,inserting a catheter over the tracking member so the tracking memberextends through a first lumen of the catheter and the cutting members donot extend through the first lumen, and moving the cutting members awayfrom the tracking member into cutting contact with the lesion to enlargethe passageway in the body lumen and deliver the separate material tothe interior of the lesion.

Preferably, the step of inserting the cutting members and trackingmember comprises the step of inserting the cutting members and trackingmember through a lumen of a catheter.

In some embodiments, the catheter through which the cutting and trackingmembers are initially inserted is the same catheter subsequentlyinserted over the tracking member. In other embodiments, a differentcatheter is utilized. In some embodiments, the step of moving thecutting members comprises the step of expanding a balloon of thecatheter.

In preferred embodiments, the cutting members and tracking member arewires and are attached at their distal end and inserted as a unit intothe vessel.

In another aspect, the present invention provides a device for treatinga lesion in a body lumen to enlarge a passageway in a body lumencomprising a plurality of cutting members having a proximal portion, adistal portion and a separate material and a tracking member having aproximal portion and distal portion. The cutting members and trackingmember are connected at their distal portions and unconnected at theirproximal portion and insertable into the vessel as a unit, the cuttingmembers configured for movement in a direction transverse to alongitudinal axis of the tracking member to widen a gap between thecutting members and tracking member at least at a distal region.

In some embodiments, the cutting members each have a cutting surface ona first surface opposite a second surface facing the tracking member. Insome embodiments, the cutting members have a cutting surface with a flatedge on an edge opposite a surface facing the tracking member. Theseparate material is preferably disposed on or in the cutting surfaceportion of the cutting member. The surface opposite the cutting surfacecan have a convex or concave surface. In some embodiments, the trackingmember and cutting members are connected by twisting of the members atthe distal portion.

In some embodiments, the tracking member has a coil at a distal end. Ashrink wrap can be positioned over a connection region of the cuttingmembers and tracking member. The tracking member can include a pluralityof marker bands.

In some embodiments, the cutting members are substantially circular incross-section in a proximal region and substantially triangular in crosssection in a distal region. In some embodiments, the cutting surface isformed only in a distal region of the cutting members. In someembodiments, the separate material can be placed only in the distalregion of the cutting members to apply the material into the tissuebeing cut.

In another aspect, the present invention provides a system for treatinglesions in a body lumen to enlarge a restriction in the body lumencomprising a catheter having a lumen and an expandable portion and acutting assembly including a plurality of cutting members having aseparate material associated therewith and a tracking member, thetracking member attached to at least one of the cutting members. Theexpandable portion of the catheter is expandable to move the cuttingmembers in a direction transverse to a longitudinal axis of the trackingmember, the cutting members having a cutting surface configured to treatthe lesion to enlarge a passageway in the body lumen when moved by theexpandable portion of the catheter and deliver the separate material toan interior of the lesion.

In preferred embodiments, the cutting members and tracking member arenot connected at the proximal regions and are connected at distalregions thereof and inserted as a unit through the lumen of thecatheter. In some embodiments, the expandable portion comprises aninflatable balloon.

The tracking member can have a coil at a distal end. Marker bands can beprovided on the tracking member. A shrink wrap can be positioned over aconnection region of the cutting members and tracking member.

In some embodiments, each of the cutting members has a cutting edgeopposite an edge facing the tracking member, and expansion of a portionof the catheter forces the cutting edges into diseased narrowed sectionswithin the lesion.

In some embodiments, the length of the tracking member can exceed thelength of the cutting members.

In some embodiments, the cutting members have a first portion of a firstconfiguration and a second portion of a second configuration, the secondportion including a cutting surface and the first portion beingatraumatic. In such embodiments, the separate material can be placed inor on the cutting surface and not on the atraumatic first portion. Aheight of the second portion can be less than a height of the firstportion.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiment(s) of the present invention are described hereinwith reference to the drawings wherein:

FIG. 1 is a perspective view of a conventional balloon catheter and afirst embodiment of the cutting wire assembly (unit) of the presentinvention and showing the balloon expanded;

FIG. 1A is a perspective view of the cutting assembly of FIG. 1;

FIG. 1B is a perspective view similar to FIG. 1A showing the shrink wrapover a distal portion;

FIG. 2A is an enlarged perspective view of the area of detail of FIG. 1showing a portion of the cutting wire in accordance with one embodiment;

FIG. 2B is a perspective view similar to FIG. 2A showing anotherembodiment of the cutting wire;

FIG. 2C is a perspective view similar to FIG. 2A showing yet anotherembodiment of the cutting wire;

FIG. 2D is a perspective view similar to FIG. 2A showing anotherembodiment of the cutting wire;

FIG. 2E is a perspective view similar to FIG. 2A of yet anotherembodiment of the cutting wire;

FIG. 3A is a perspective view of another embodiment of the cutting wireassembly;

FIG. 3B is a close up perspective view of a distal portion of thecutting assembly of FIG. 3A.

FIG. 3C is a close up view similar to FIG. 3 showing an alternateembodiment of the cutting assembly.

FIG. 4A is a cross-sectional view of the cutting wire taken along line4A-4A of FIG. 3B;

FIG. 4B is a cross-sectional view of the cutting wire taken along line4B-4B of FIG. 3B;

FIGS. 5-5E illustrate the method steps for use of the cutting wireassembly of FIG. 1, the drawings showing cross-sectional views, wherein

FIG. 5 illustrates a conventional balloon catheter inserted over aconventional guidewire;

FIG. 5A illustrates withdrawal of the conventional guidewire;

FIG. 5B illustrates insertion of the cutting and tracking members of thepresent invention through the balloon catheter lumen;

FIG. 5C illustrates withdrawal of the balloon catheter leaving thecutting and tracking members within the vessel lumen;

FIG. 5D illustrates the balloon catheter inserted over the trackingmember; and

FIG. 5E illustrates expansion of the balloon of the balloon catheter toforce the cutting wire into cutting contact with the lesion.

FIG. 6 is a perspective view of a conventional balloon catheter and analternate embodiment of the cutting wire assembly (unit) of the presentinvention, and showing the balloon expanded;

FIG. 6A is perspective view of an alternate embodiment of the cuttingwire assembly;

FIG. 7 is a perspective view of the area of detail of FIG. 6 showing aportion of the cutting wire in accordance with one embodiment;

FIG. 8 is a cross-sectional view of the cutting wire taken along line8-8 of FIG. 7;

FIGS. 8A-8E are views similar to FIG. 8 showing cross-sectional views ofalternate embodiments of the cutting wire of the present invention;

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 6;

FIG. 9A is a cross-sectional view of another embodiment of the cuttingwire assembly of the present invention;

FIG. 10 is a partially exploded side view of the cutting wire assemblyof FIG. 6;

FIGS. 11-11E illustrate the method steps for use of the cutting wireassembly of FIG. 6, the drawings showing cross-sectional views, wherein:

FIG. 11 illustrates a conventional balloon catheter inserted over aconventional guidewire;

FIG. 11A illustrates withdrawal of the conventional guidewire;

FIG. 11B illustrates insertion of the cutting and tracking elements ofthe present invention through the balloon catheter lumen;

FIG. 11C illustrates withdrawal of the balloon catheter;

FIG. 11D illustrates the balloon catheter inserted over the trackingelement; and

FIG. 11E illustrates expansion of the balloon of the balloon catheter toforce the cutting elements into cutting contact with the lesion.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawings wherein like reference numeralsidentify similar or like components throughout the several views, thecutting assembly of the present invention includes a cutting member (orelement) and a tracking member (or element). In some embodiments, asingle cutting member is provided; in alternative embodiments, multiplecutting members are provided. The cutting member(s) of the presentdisclosure have a separate material such as a drug or therapeutic agentthereon or therein for delivery to an interior of a lesion.

The various devices of the present invention disclosed herein functionto treat the stenotic lesion inside the vessel wall, thereby opening orenlarging the passageway in the vessel which was restricted. Thestenosis can be a result of plaque buildup, endothelial growth, bloodclots, etc. The device can also be used to treat other lesionsrestricting passageways in other body lumens. The drug or therapeuticmaterial associated with the cutting member enables the material toaccess the interior of the lesion which can advantageously deliver adrug to enhance breaking up the lesion. In some embodiments, thematerial can be a drug or agent to promote natural production of tPA tohelp dissolve clots in the body. In some embodiments, the material canbe drug or agent to prevent clot formation such as heparin.Anti-platelet and anti-coagulants can also be delivered by the cuttingmember. The material can be applied as a coating, applied byelectroplating, impregnated, or embedded in the cutting wire to leachinto the lesion. Other ways of applying (associating) the separatematerial with the cutting wire are also contemplated.

With initial reference to the single cutting member embodiments of FIGS.1-5, an assembly 10 in accordance with one embodiment of the presentinvention includes a tracking member, designated generally by referencenumeral 30 and preferably in the form of a wire, and a cutting member,designated generally by reference numeral 20 and preferably in the formof a wire. As discussed in more detail below, the tracking wire 30 andcutting wire 20 are preferably attached at a distal portion so they areinsertable as a unit. The wire assembly 10, as described below, can beused with a conventional catheter, such as an angioplasty catheter.

With reference to FIGS. 1 and 5C, cutting member in the form of a wire20 has a distal portion 23 which is connected to a distal portion 32 ofa tracking member in the form of a wire 30. In the illustratedembodiment, a distalmost tip 23 of the cutting wire 20 is attached tothe tracking or guidewire 30. One way of attachment is to twist thewires together. Other methods of attachment are also contemplated suchas welding, bonding or placement of a separate element such as a collarover the end of the wires to frictionally engage the wires. The cuttingwire 20 remains unattached proximal of the distal connection(attachment) region to enable it to be separated from the tracking wire30, e.g., moved transversely with respect to the longitudinal axis ofthe tracking wire 30. In FIG. 5C, the initial position of the wires 20,30 are shown; in FIGS. 5D and 5E the wires 20, 30 are further separatedas described in detail below.

Tracking member has a coil tip 33 for flexibility. A heat shrink wrap 35can be placed over the connection region of the cutting wire 20 and atracking wire 30. Marker bands 34 can be provided for imaging.

Note the tracking wire and cutting wire can be of substantially the samelength, both extending out of the body for reinsertion of a catheterover the tracking wire as described below. Alternatively, they can be ofdifferent lengths. For example, in some embodiments the length of thecutting wire 20 exceeds the length of the tracking wire 30.

Various configurations of the cutting wire 20 are illustrated toeffectively treat lesions. In the embodiment of FIG. 2A, the wire 70 issubstantially triangular in cross section forming a V-shaped cuttingsurface 72 on a first surface opposite a second surface facing thetracking wire 30. The side surfaces can be substantially planar asshown. In the embodiment of FIG. 2B, a cutting edge 76 on first surface78 a of cutting wire 78 with a substantially planar outer edge extendsfrom the substantially planar base 79. In FIG. 2C, a surface 82 of thewire 80 opposite the cutting surface 84 and facing the tracking wire 30is concave. This surface 82 can conform to the outer surface of thecatheter balloon. Two or alternatively three sides of the cutting wirecan be concave as in sides 86 a, 86 b, 86 c of wire 85 of FIG. 2D oralternately convex. In the embodiment of FIG. 2E, wire 88 is trapezoidalin cross section with a cutting surface 89 on the outer surface. Othershapes are also contemplated, including but not limited to polygonalshapes that are substantially: square, rectangular, rhombus, hexagonal,pentagonal, octagonal, diamond shaped, etc. A round or oval wirecross-section with a sharpened surface is also contemplated. Caltropshapes and upside down T-shapes are also contemplated. These wire shapescan be utilized in the various cutting wire embodiments disclosedherein.

A separate material such as a drug or therapeutic agent is placed on orin the cutting surfaces of the wire. For example, the material could beplaced on surface 72 and/or the angled surfaces of FIG. 2A, on cuttingedge 76 and/or its side surfaces of FIG. 2B, on cutting surface 84and/or the angled surfaces of FIG. 2C, on the cutting edge and/orconcave surfaces 86 a-86 c in FIG. 2D and on cutting surface 89 and/orthe side surfaces of FIG. 2E. In certain instances, all surfaces can becoated with the material in manufacturing, including the surface facingthe balloon, to ease the application of material during manufacturing.

Note, if desired, only a portion of the cutting wire (member) can havethe cutting edge or surface, e.g. the distal region, with a remainingportion being atraumatic and non-cutting. This is shown for example inthe embodiment of FIGS. 3A and 3B where wire 51 of cutting assembly 50has a distal portion having a cutting edge 54. (Although shown as asubstantially triangular cross-section, other cross-sectional shapes arealso contemplated including those discussed above). Proximal of distalportion 52, the portion 56 is atraumatic and can be substantiallycircular in cross-section as shown in FIG. 4B. (Other shapes are alsocontemplated). The distal region of wire 51 can be conical and can havean atraumatic surface. Note the height of the cutting surface region canbe less than the height (e.g. diameter) of the atraumatic portion 56. Inthese embodiments, the separate material can be applied if desired onlyto the distal portion of the cutting member having the cutting edge,e.g., cutting edge 54 (and/or its angled surfaces), with the remainingatraumatic portion, e.g., portion 56, lacking the separate material,e.g., being uncoated. Alternatively, the material can also be applied toor associated with other portions of the cutting member or to the entirecutting member.

A coil such as coil 33 can be provided at the distal tip of trackingmember (wire) 55. Several marker bands 58 are provided on tracking wire55 for imaging. A heat shrink wrap such as shrink wrap 35 of FIG. 1Bwhich covers the distal and connecting region of wires 20 and 30 can beprovided over the distal tip and connection region of the cutting andtracking wires 51, 55 of FIG. 3B. The shrink wrap can be composed ofPET, PTFE, FEP or other materials. The marker bands 58 can be located asshown or placed in other regions. For example, the proximal marker bandcan be positioned on the circular part of the cutting member (proximalof the cutting surface) and the distal marker band can be wrapped aroundboth the cutting member and tracking member at a location where they arejoined. This is shown in the alternate embodiment of FIG. 3C havingdistal marker band 58′ and proximal marker band 58″. Otherwise thedistal portion 52′ of the assembly is the same as distal portion 52 ofFIG. 3B and therefore provided with the same reference numerals.

One method of use of the wire assembly 10 of the present invention willnow be described. The method is described for using wire assembly 10,but it should be appreciated that the same method can be used for wireassembly 50 (and for the other cutting wire configurations). Initially,a conventional catheter 100, such as conventional angioplasty catheter,is inserted over a conventional guidewire G to the treatment site asshown in FIG. 5. Guidewire G extends through a lumen 62 in the catheter60. Access to the vessel can be obtained through the femoral artery orvein for example. Note the proximal end of the catheter 60 and guidewireG extend outside the patient's body. The angioplasty catheter 60 has aninflatable balloon 64 which is in fluid communication with an inflationlumen of the catheter as is conventional. At the target site, inflationof the balloon 64 expands the balloon 64 to expand the lesion B andwiden the lumen of the vessel V.

If the stenotic lesion cannot be successfully opened by a conventionalballoon due to lack of force, the wire assembly 10 (or assembly 50) ofthe present invention can be utilized. In this case, the guidewire G isremoved from the guidewire lumen 62 of the catheter 60 (see FIG. 5A) andthe wire assembly 10 (or 50) is inserted through the lumen 62 as shownin FIG. 5B. Thus, by insertion through the lumen 62, the trackingguidewire 30 (or 55) and cutting wire 20 (or 51) of wire assembly 10 (or50) are inserted to the target site.

Next, the catheter 60 is removed from the treatment site and vessel, andremoved from the body, leaving the wire assembly 10 at the target siteas shown in FIG. 5C. The catheter 60 is then reinserted over proximalend of tracking wire 30. Note that instead of reinserting the samecatheter used in the step of FIG. 5, alternatively, a different ballooncatheter (or catheter with other expandable member) can be inserted. Ineither event, the catheter is inserted over the proximal portion of thetracking wire 30 such that the tracking wire 30 extends through thelumen 62; however, cutting wire 20 remains outside the lumen 62 and thusdoes not extend through lumen 62 as shown in FIG. 5D. In this manner,the tracking wire 30 provides a guide for the catheter 60 to the targetsite, while the cutting wire 20 remains adjacent an outer surface of thecatheter 60 for subsequent expansion into contact with the lesion. Asshown in FIG. 5D, there is an increased gap 65 between the cutting wire20 and tracking wire 30 caused by the catheter 60 positioned between thetwo wires 20, 30.

To expand or move the wire 20 transversely with respect to thelongitudinal axis of the tracking wire 30 (and transverse to thelongitudinal axis of the catheter 60), the balloon 64 is inflated,forcing the cutting wire 20 radially and into contact with the lesion Bso the cutting edge or surface can treat the lesion. The cutting wire 20can penetrate the lesion thereby delivering the drug or agent to theinterior of the lesion to help break up the lesion and/or to deliver thedrug or agent to promote natural production of TPA to help dissolveclots. The cutting wire 20 can also be used to deliver a material toprevent clots from forming such as by applying heparin. It should beappreciated that instead of a balloon, a mechanical expander or otherstructure can be used to force the cutting wire 20 into contact with thelesion. If desired, the balloon 64 can be deflated and the wire assemblyeasily rotated to another position for subsequent transverse movement bythe cutting wire into contact with another region of the lesion B. Inthis manner, the select portions of the stenosis can be treated, as thecutting wire 20 is expanding in one direction. The cutting wire assembly50 can be used in a similar manner.

As can be appreciated, the method described above utilizes the samecatheter for the initial step (FIG. 5) as well as for the subsequentstep of reinsertion for placement only over the tracking wire 30 (FIG.5D). However, it is also contemplated that a different catheter can beused for insertion over tracking wire 30 in the step of FIG. 5D.

Alternative embodiments having multiple cutting wires are illustrated inFIGS. 6-11. More specifically, cutting assembly 110 of one embodimentincludes a tracking member, designated generally by reference numeral140, preferably in the form of a wire, and two cutting members,designated generally by reference numerals 120 and 130, and preferablyin the form of wires. As discussed in more detail below, the trackingwire 140 and cutting wires 120, 130 are preferably attached at a distalportion so they are insertable as a unit, and are unattached at theirproximal portions. The wire assembly 110, as described below, can beused with a conventional catheter, such as an angioplasty catheter.Additionally, although two cutting wires are shown in FIG. 6, spacedabout 180 degrees apart, different spacing is also contemplated.Additionally, more than two cutting wires can be provided, e.g. threecutting wires such as wires 180, 181, 182 of FIG. 9A, four cuttingwires, etc. The three cutting wires 180, 181, 182, can be equidistantlyspaced apart encircling tracking wire 190 as shown or spaced atdifferent distances.

With reference to FIGS. 6, 10 and 11C, the first cutting member is inthe form of a wire 120 and has a distal portion 122 which is connectedto a distal portion 142 of a tracking member in the form of a wire 140.In the illustrated embodiment, a distalmost tip 123 of the cutting wire120 is attached to the tracking guidewire 140. Similarly, the secondcutting member is in the form of a wire 130 and has a distal portion 132which is connected to the distal portion 142 of the tracking member 140.In the illustrated embodiment, a distalmost tip 133 of the cutting wire130 is attached to the tracking guidewire 140. One way of attachment ofthe wires 120, 130 to wire 140 is to twist the wires together. Othermethods of attachment are also contemplated such as welding, bonding orplacement of a separate element such as a collar, e.g. collar 145, overthe end of the wires to frictionally engage the wires. The cutting wires120, 130 remain unattached proximal of the distal connection to enablethem to be separated from the tracking wire 140, e.g. moved transverselywith respect to the longitudinal axis of the tracking wire 140. In FIGS.11B and 11C, the initial position of the wires are shown; in FIGS. 11Dand 11E the wires are separated as described in detail below.

A coil 157 can be provided at the tip such as illustrated in FIG. 6.Several marker bands 158 can be provided on tracking wire 140 forimaging. The marker bands can be placed as shown or in other regions,including on the cutting member(s). For example, the proximal markerband can be positioned on a circular part of the cutting members(proximal of the cutting surfaces) and the distal marker band can bewrapped around both the cutting member and tracking member at a locationwhere they are joined, e.g., on collar 145. In the alternate embodimentof FIG. 6A, a shrink wrap 153 can be provided over the connection regionof the tracking wire 140′ and cutting wires 120′, 130′ of cuttingassembly 110′. The cutting assembly 110′ can also include a coil similarto coil 157 and a collar similar to collar 145.

Note the tracking wire and cutting wires can be of substantially thesame length, both extending out of the body for reinsertion of acatheter over the tracking wire as described below. Alternatively, theycan be of different lengths. For example, one or more of the cuttingwires can have a length exceeding the length of the tracking wire.

Various configurations of the cutting wires 120, 130 are illustrated toeffectively treat lesions. In the embodiment of FIG. 6, the wires 120,130 are substantially circular in cross-section until a transitionregion, i.e. region 125, where it transitions to a wire substantiallytriangular in cross section forming a V-shaped cutting surface 127 on afirst surface opposite a second surface 129 facing the tracking wire 140(FIG. 8). A concave or convex surface can be formed on one, two or allthree sides (see e.g. wire 170 of FIG. 8A). Alternately, a substantiallyplanar surface can be formed on one, two, or all sides. A concavesurface on the side opposite the cutting edge helps to conform to theouter surface of the catheter balloon.

Other cross-sectional shapes of the cutting wires 120, 130 are alsocontemplated, including but not limited to, polygonal shapes that aresubstantially: rectangular, square, trapezoidal (see e.g. wire 175 ofFIG. 8B), hexagonal, pentagonal, octagonal, diamond shaped, etc. A roundor oval wire cross-section with a sharpened surface is alsocontemplated. In the embodiment of FIG. 8C, a rhombus shaped wire 180 isillustrated. This shape facilitates cutting if the cutting wire isrotated. FIG. 8D illustrates a caltrop shape wire 184 configured so thatone point will always point upward. FIG. 8E illustrates an upside downT-shape wire 188. The base of wire 188 can be convex or concave. Thesewire shapes can be utilized in the various cutting wire embodimentsdisclosed herein, including the single cutting wire embodiments.

A separate material such as a drug or therapeutic agent is placed on orin the cutting surfaces of one or more of the wires. For example, thematerial could be placed on surface 127 and/or the side surfaces of FIG.8, and on the cutting edges and surfaces of the wires of FIGS. 8B-8E. Incertain instances, all surfaces can be coated with the material inmanufacturing, including the surface facing the balloon, to ease theapplication of material during manufacturing.

It is contemplated that cutting wire 130 has the same configuration ascutting wire 120. However, in alternate embodiments, the cutting wire130 can have an alternate configuration, including but not limited to,any of the foregoing cross-sectional wire shapes. In either embodiment,cutting wires 120 and 130 are coated or otherwise have separate materialassociated therewith.

Note, if desired, only a portion of the cutting wires 120, 130 can havethe cutting edge or surface, e.g. the distal region, with a remainingportion being atraumatic and non-cutting. This is illustrated in FIG. 7,where the circular cross-section at a more proximal region isatraumatic. Note a region distal of the cutting portion can beatraumatic, e.g. can transition back to a substantially circularcross-section. In these embodiments, the separate material can beapplied or embedded (associated) if desired only to the distal regionsof the cutting members having the cutting edge with the remainingproximal atraumatic portion lacking the separate material, e.g., beinguncoated. Alternatively, the material can be embedded or applied to(associated with) other portions of the cutting members or the entirecutting member. It is also contemplated in some embodiments that not allof the cutting members have the separate material associated therewithas it may be desirable to have only one or a selected few of multiplecutting members contain the separate material. The wires can also have aconical tip as in the embodiment of FIG. 3B.

One method of use of the wire assembly 110 of the present invention willnow be described. Wire assembly 110′ would be used in the same manner.Initially, a conventional angioplasty catheter 100 is inserted over aconventional guidewire G to the treatment site as shown in FIG. 11.Guidewire G extends through a lumen 102 in the catheter 100. Access tothe vessel can be obtained through the femoral artery or vein forexample. Note the proximal end of the catheter 100 and guidewire Gextend outside the patient's body. The angioplasty catheter 100 has aninflatable balloon 104 which is in fluid communication with an inflationlumen of the catheter as is conventional. At the target site, inflationof the balloon 104 expands the balloon to expand the lesion B and widenthe lumen of the vessel V.

If the stenotic lesion cannot be successfully opened by a conventionalballoon due to lack of force, the wire assembly 110 (or 110′) of thepresent invention can be utilized. In this case, the guidewire G isremoved from the guidewire lumen 102 of the catheter 100 (see FIG. 11B)and the wire assembly 110 is inserted through the lumen 102 as shown inFIG. 11B. Thus, by insertion through the lumen 102, the trackingguidewire 140 and cutting wires 120, 130 of wire assembly 110 areinserted to the target site.

Next, the catheter 100 is removed from the treatment site and vessel,and removed from the body, leaving the wire assembly 110 at the targetsite as shown in FIG. 11C. The catheter 100 is then reinserted over theproximal end of tracking wire 140. Note that instead of reinserting thesame catheter used in the step of FIG. 11, alternatively, a differentballoon catheter can be inserted. In either event, the catheter 100 isinserted over the proximal portion of the tracking wire 140 such thatthe tracking wire 140 extends through the lumen 102; however, cuttingwires 120 and 130 remain outside the lumen 102 as shown in FIG. 11D. Inthis manner, the tracking wire 140 provides a guide for the catheter 100to the target site, while the cutting wires remain adjacent an outersurface of the catheter 100 for subsequent expansion into contact withthe lesion. As shown in FIG. 11D, there is an increased gap 125 betweenthe cutting wires 120, 130 and tracking wire 140 caused by the catheter100 positioned between the tracking wire 140 and the two wires 120, 130.

To expand or move the cutting wires 120, 130 transversely with respectto the longitudinal axis of the tracking wire 140 (and transverse to thelongitudinal axis of the catheter 100), the balloon 104 is inflated,forcing the cutting wires 120 and 130 into contact with the lesion B sothe cutting edge or surface can treat the lesion. The cutting wires 120,130 can penetrate the lesion thereby delivering the material, e.g., thedrug or therapeutic agent, to the interior of the lesion to help breakup the lesion and/or to promote natural production of tPA to helpdissolve clots. In some embodiments, the material can be a drug or agentto prevent clot formation such as heparin. Anti-platelet andanti-coagulants can also be delivered by the cutting members. Thematerial can be applied as a coating, applied by electroplating,impregnated, or embedded in one or more of the cutting wires to leachinto the lesion. Other ways of applying (associating) the separatematerial with one or more of the cutting wires are also contemplated.

It should be appreciated that instead of a balloon, a mechanicalexpander or other structure can be used to force the cutting wires 120,130 radially and into contact with the lesion. If desired, the balloon104 can be deflated and the wire assembly easily rotated to anotherposition for subsequent transverse movement of the cutting wires by theballoon into contact with another region of the lesion B to treat selectportions of the stenosis.

As can be appreciated, the method described above utilizes the samecatheter for the initial step (FIG. 11) as well as for the subsequentstep of reinsertion for placement only over the tracking wire 140 (FIG.11D). However, it is also contemplated that a different catheter can beused for reinsertion over only the tracking wire 140.

The material on or in the cutting wire or wires of the aforedescribedembodiments enable delivery of a drug or therapeutic agent to theinterior, e.g., middle, of the lesion. The drug or therapeutic agent canhelp break up the lesion and can include for example heparin, tPA,urokinase, etc. Drugs or agents can also be utilized which promotenatural production of tPA which helps dissolve clots in the body. Drugsor agents can also be used which prevent clot formation. Drugs or agentshaving a beneficial effect against restenosis, e.g., anti-restenosisagents such a taclitaxel, can be used. Anti-platelet, anti-thrombin,anti-coagulants and anti-inflammatory agents can also be utilized.Various known methods can be utilized to apply the drug or agent to oneor more of the cutting wires including but not limited to thosedescribed herein.

It is also contemplated that different drugs and therapeutic agents canbe placed on or in different portions of the cutting wire (wires).

Also, as shown, a single balloon is utilized to expand both wiressubstantially simultaneously. It is also contemplated that a separateballoon or separate expansion of the single balloon can be used to movethe wires 120, 130 independently/separately.

As can be appreciated, the wire assemblies disclosed herein canaccommodate balloon catheters having relatively small guidewire lumens.

Also, although access is described through the femoral artery, otherapproaches to the target site are also contemplated. Additionally,although described for use to treat lesions in vessel lumens, thedevices disclosed herein can also be used to remove other structuresconstricting the passageway in the vessel or in other body lumens.

The cutting and tracking components are illustrated as wires, but otherstructures for the cutting member and tracking member are alsocontemplated such as a hard plastic tube or a metal hypotube. The metalhypotube can be formed with a cutting surface or alternatively have acutting member such as a cutting tube attached thereto.

The device, e.g., the cutting member and/or tracking member, can includea lubricious coating such as PTFE.

The cutting wire assemblies of the present invention as described can beused in various vessels including for example, veins such as the femoralveins, grafts such as dialysis grafts, etc. Other vessels are alsocontemplated such as use in carotid arteries, coronary arteries, thedescending aorta and renal arteries, the external iliac and internaliliac arteries and the common femoral and deep femoral arteries.Applications for the devices disclosed herein include, but are notlimited to, treating stenotic venous and arterial anastomosis, lesionsresistant to conventional angioplasty, stent restenosis, and vesselswith buildup of intima, etc.

While the above description contains many specifics, those specificsshould not be construed as limitations on the scope of the disclosure,but merely as exemplifications of preferred embodiments thereof. Thoseskilled in the art will envision many other possible variations that arewithin the scope and spirit of the disclosure as defined by the claimsappended hereto.

What is claimed is:
 1. A device for treating a lesion in a body lumen toenlarge a passageway in the body lumen, the device comprising at leastone cutting member and a tracking member, the at least one cuttingmember having a proximal portion, a distal portion, a cutting surfaceand a separate material associated therewith, the tracking member havinga proximal portion and distal portion, the cutting member and trackingmember being connected at a distal portion and insertable into the bodylumen as a unit, the cutting member configured for movement in adirection transverse to a longitudinal axis of the tracking member towiden a gap between the cutting member and tracking member at least at adistal region and to apply the separate material to an interior of thelesion.
 2. The device of claim 1, wherein the cutting surface is on afirst surface opposite a second surface facing the tracking member. 3.The device of claim 2, wherein the cutting surface is formed only in adistal region of the cutting member and the separate material is onlyassociated with the distal region of the cutting member having thecutting surface.
 4. The device of claim 1, wherein the tracking memberincludes a plurality of marker bands.
 5. The device claim 1, wherein theat least one cutting member includes a plurality of cutting members, theplurality of cutting members are connected at a distal portion to thetracking member and inserted as a unit through a lumen of the catheter.6. The device of claim 1, in combination with a catheter having a lumenand an expandable portion, wherein the cutting surface is configured totreat the lesion to enlarge the passageway in the body lumen when movedby the expandable portion of the catheter to widen the gap between thecutting members and tracking member.
 7. The device claim 1, wherein thecutting member has a first portion of a first configuration and a secondportion of a second configuration, the second portion including acutting surface and the first portion being atraumatic, wherein theseparate material is placed on the second portion and not on the firstportion.
 8. The device of claim 7, wherein a height of the secondportion is less than a height of the first portion.
 9. The device of anyof claim 1, wherein the tracking member has a coil at a distal tip, andfurther comprising shrink wrap over a connection region of the trackingand cutting members.
 10. The device of any of claim 1, wherein thecutting member is a wire and the tracking member is a wire.
 11. Thedevice of claim 1, wherein the separate material is a thrombolyticagent.
 12. The device of claim 1, wherein the separate material is ananti-coagulant.
 13. The device of claim 1, wherein the cutting member issubstantially circular in cross-section in a proximal region andsubstantially triangular in cross-section in a distal region.
 14. Thedevice of claim 1, wherein the separate material is a material appliedto an external region of the cutting member.
 15. The device of claim 1,wherein the separate material is embedded in the cutting member andleaches into the lesion.
 16. A method of treating a lesion in a bodylumen, the method comprising: inserting a tracking member and at leastone cutting member having a separate material associated therewith intothe body lumen; inserting a catheter over the tracking member so thetracking member extends through a first lumen of the catheter and thecutting member does not extend through the first lumen; and moving thecutting member away from the tracking member into cutting contact withthe lesion to enlarge a passageway in the body lumen and apply theseparate material to an interior of the lesion.
 17. The method of claim16, wherein the step of inserting the at least one cutting member andtracking member comprises the step of inserting the at least one cuttingmember and tracking member through a lumen of an angioplasty catheter,the angioplasty catheter being different than the catheter inserted overthe tracking member.
 18. The method of claim 16, wherein the step ofinserting the at least one cutting member and tracking member comprisesthe step of inserting the at least one cutting member and trackingmember through a lumen of the same catheter subsequently inserted overthe tracking member.
 19. The method of claim 16, wherein the step ofmoving the cutting member away from the tracking member includesexpanding an expandable balloon of a catheter, the step of expanding theballoon causes the at least one cutting member to be moved radially withrespect to the catheter and a gap between the at least one cuttingmember and tracking member to widen.
 20. The method of claim 16, whereinthe at least one cutting member and tracking member are attached at adistal end and inserted as a unit through the lumen of the catheter.